The Abyei area’s future has been up in the air since the secession of Southern Sudan. The tiny region is extremely rich in oil but very split on whether to join the south or remain part of the Khartoum-based nation. A referendum is expected in the future.

But the referendum was expected to be very close, and the move to chase large numbers of pro-South residents out and move in pro-regime nomads could sway the vote decisively toward keeping the area under the Bashir government’s control.